Detailed explanation of the interactive use of PHP and MySQL_PHP tutorial

Detailed explanation of the interaction between PHP and MySQL
1. Create the code to automatically connect to the database and generate some necessary codes. If we carefully study the connection function of the database, we will find this line of code.
$link_id=@mysql_connect($hostname,$username,$password);
So we just add the following code to the include file connect.inc. connect.inc$username='phpstar';$password='phpstar';$dbname='script';
$tablename='php_script';$link_id= mysql_connect($hostname,$username,$password);
if (! $link_id){ echo '

';
echo 'Connection to PHP has failed.';echo '';exit(); }?>
Add this program to every PHP script , so that a database connection is established when the script is run. Because our program is interactive and we need to process the information entered by the user, the following code should also be added to the file.
if (count($HTTP_GET_VARS)) /*If the user information is input in GET mode, read the data*/
{ while ( list($key, $value) = each ($HTTP_GET_VARS)) /*Function list() and each() cooperate to process input data*/
{ $arr_request[strtolower($key)] = $value; } }
/*The function strtolower() converts the distinguishing key string to lowercase, which is beneficial to subsequent programming, and forms them into an array*/
if (count($HTTP_POST_VARS)) /*User Information is entered in POST mode*/
{ while (list($key, $value) = each ($HTTP_POST_VARS))
{ $arr_request[strtolower($key)] = $value; } } //We Also define the HTML output each time
function html_header($title){ echo ' '; }function html_footer()
{ global $link_id;@mysql_close($link_id);echo ' ';}//There is also an error message processing
function html_error_exit($msg){ $errno = mysql_errno(); /*Get the error message code*/
$error = mysql_error(); /*Get the error information, the two work together for troubleshooting*/
echo ' ';echo $msg;
echo "
Error: ($errno) $error
";echo '';exit(); }?>
Okay! Let’s do it Some commonly used codes are placed here, which is convenient to use. 2. There are two methods for creating database tables: entering commands in a DOS environment, but it is easy to make mistakes.
Using programs, even if mistakes are made, it is easy to modify them. .We use a program to create a data table. Because our program needs to be universal, the fields in the table are not important. Here we just simply create one. The table has the following management fields:
key_script This is a An auto-increment field, which ensures that the records in the table are unique. date_created This is a date field, which stores the time when the record was created
data_updated This is also a date field, which stores the time when the record was last updated
flag_deleted stores whether the record has been deleted, "Y": the record has been deleted, "N": the record has not been deleted, you can use the following fields to store information. script_name program name
script_size program bytes script_describe program Brief description author_name program author name author_email program author's email
author_homepage Create the program under the program author's homepage: createTable.php$str_sql="create table php_script(
key_script int(10) unsigned DEFAULT '0' NOT NULL auto_increment,
date_created datetime DEFAULT '0000-00-00 00:00:00',
date_updated datetime DEFAULT '0000-00-00 00:00 :00',
flag_deleted enum('Y','N') DEFAULT 'N' NOT NULL,
script_name VARCHAR(20) NOT NULL,script_size VARCHAR(10) NOT NULL,
script_describe VARCHAR( 200) NOT NULL,author_name VARCHAR(20) NOT NULL,
author_email VARCHAR(20) NOT NULL,author_homepage VARCHAR(30) NOT NULL,
primary key (key_script))";$result=mysql_db_query($dbname ,$str_sql,$link_id);
if ($result){echo "ok! Table $tablename has been created!";}else{echo "Failed!";}
?>OK! Our The table is built! 3. Generate the insert record code program. It seems that we should display the record first and then insert the record, but since we don't have a record yet, we put this step first.
First, create an HTML form to allow users to enter relevant information. Second, create the MySQL code that can insert the form information.good! Let's start. The form style is as follows: Program name: File size: Program description: Author name:
Author email address: Author's homepage: The MySQL code that can insert form information is as follows: script_insert_action.phprequire( 'connect.inc');if($arr_request['action']=='insert'){
$current_date=date('Y-m-d H:i:s');/*Press the current time to YYYY-MM -DD ​​HH:MM:SS arrangement*/
/*The SQL code will be dynamically generated below, in which the auto-increment fields we define are generated by MySQL itself*/
/*In addition, the default value of the flag_deleted field It's "N", so we don't need to mention these two items here*/
/*Everyone knows: PHP strictly distinguishes the functions of single quotes (') and double quotes ("). And our author The name is in the array*/
/*We need to reference the array like this: $arr_request['author_name'], note that there are single quotes (')*/
/*When we enter the value of the insert statement It should be like this: VALUES('$current_date') */
/*If we don't deal with these semicolons, this will happen: VALUES('$arr_request['author_name']') */
/*Can PHP handle this situation? Of course not, so we think of ways to deal with it*//*Here, we use the following technique to avoid this problem; of course, there are other methods you can think of first. Think about it! */
$script_name=$arr_request['script_name'];
$script_size=$arr_request['script_size'];
$script_describe=$arr_request['script_describe'];
$author_name=$arr_request['author_name'];
$author_email=$arr_request['author_email'];
$author_homepage=$arr_request['author_homepage'];/*With this replacement, the processing will be much better */
$str_sql="insert into $tablename(date_created,date_updated,script_name,
script_size,script_describe,author_name,author_email,author_homepage)VALUES(
'$current_date','$current_date','$ script_name','$script_size',
'$script_describe','$author_name','$author_email','$author_homepage')";
$result=mysql_db_query($dbname,$str_sql,$link_id) ;/* Here is a simple feedback to the user*/
if (!$result){html_error_exit('MySQL insertion command failed!');}else(html_header('Success');
echo"< center> ";echo('MySQL insertion command successful');echo"
";echo"html_footer();)?>
OK! The insert record function is completed!